Tea tree oil from an Australian tree has been used for at least a century as a topical medicine for both humans and animal skin conditions.  It is antimicrobial, anti-inflammatory, and activates monocytes.  The only common side-effect to using tea tree oil topically in low concentrations is a contact dermatitis, but this clears on stopping its use.  Creams or gels with 5% or 10% are standard. The 100% form has been used only on toe nails.

Benefit has been reported in acne, athlete's foot, dandruff, head lice, herpes labialis, impetigo, oral thrush, skin infections, seborrheic dermatitis, toenail fungus infections, and vaginal yeast.

In view of the problem with contact allergy, I would hesitate to use it for children and would first try other remedies, especially honey, which is quite effective without any contact allergy risk.  Tea tree oil can also be quite toxic if swallowed.  It should not be put in the ear.

Acne and Impetigo Helped in Randomized Studies: Positive results were reported for an ointment containing tea leaf extract in impetigo contagiosa infections. Two trials of tea tree oil preparations used for acne and methicillin-resistant Staphylococcus aureus. Herbal medicines for treatment of bacterial infections: a review of controlled clinical trials. Martin KW, Ernst E. Peninsula Medical School, Exeter, UK. J Antimicrob Chemother. 2003 Feb;51(2):241-6.

Acne: Tea Tree Oil Gel Helped: In a single blind study of 124 acne patients, a 5% tea-tree oil gel did as well as the standard 5% benzoyl peroxide lotion, reducing the number of inflamed and non-inflamed lesions (open and closed comedones), although the onset of action in the case of tea-tree oil was slower. Fewer side effects were experienced by patients treated with tea-tree oil. A comparative study of tea-tree oil versus benzoylperoxide in the treatment of acne. Bassett IB, Pannowitz DL, Barnetson RS. Camperdown, NSW. Med J Aust. 1990 Oct 15;153(8):455-8.

Burns: Don't Use Tea Tree Oil: Although "Burnaid" is sold as a mixture of tea tree oil and triclosan, it is not effective against some bacteria and can inhibit fibroblasts and epithelial cells.  Therefore, its use has been discouraged at least until good research is available. Burns. 1997 Jun;23(4):349-51. Ed: Honey is very good for burns that don't need skin grafting.

Dandruff Helped: Dandruff is related to the yeast Pityrosporum ovale. In a DB PC study of 126 patients over age 13, those using 5% tea tree oil daily over 4 weeks showed a 41% improvement vs. 11% with placebo (P <.001). There were no adverse effects. Treatment of dandruff with 5% tea tree oil shampoo. Satchell AC, Saurajen A, et al. Camperdown, NSW, Australia. J Am Acad Dermatol. 2002 Dec;47(6):852-5.

Gingivitis Helped, But Not Plaque: In a DB PC study of 49 adults with severe chronic gingivitis given either TTO-gel (2.5%), chlorhexidine (CHX) gel (0.2%), or a placebo gel to apply with a toothbrush twice daily, no adverse reactions to any of the gels were reported. The TTO group had significant reduction in bleeding and gingivitis. However,TTO did not reduce plaque scores, which tended to increase over the latter weeks of the study period. The effects of a tea tree oil-containing gel on plaque and chronic gingivitis. Soukoulis S, Hirsch R. University of Adelaide, South Australia. Aust Dent J. 2004 Jun;49(2):78-83.

Head Lice: Paw Paw, Thymol, Tea Tree Shampoo May Work: A herbal lice removal shampoo, containing an extract of paw paw, thymol, and tea tree oil, was reportedly used on 16 patients with a 100% effectiveness in removing head lice and nits in a manufacturer's study. Development of a paw paw herbal shampoo for the removal of head lice. McCage CM, Ward SM, et al. Nature's Sunshine Products, Spanish Fork, Utah. Phytomedicine. 2002 Dec;9(8):743-8.

Herpes Labialis Helped a Little: In a randomized study of 18 patients with recurrent herpes labialis applying gels 5 times a day, 3 using a 6% TTO gel and one using an inactive bodycare gel were never HSV culture-positive but their median times to presentation were 2 and 1 days, respectively, and later presentation may have contributed to the failure to detect HSV by PCR or culture. The median time to skin recovery with TTO was 9 days vs. 12.5 with placebo. TTO treatment caused a modest reduction in the median duration of culture positivity (3 compared to 4 days). There was no difference in median time to crust formation: 4 days. Viral titres appeared lower in the TTO group than in the placebo group at days 3 (5.1 x 10⁴ to 5.8 x 10⁶ pfu/mL, respectively) and 4 (10 to 2.1 x 10³ pfu/mL, respectively) after onset, but these differences did not reach statistical significance. The reduction in time to re-epithelialization seen in the TTO group was similar to reductions reported previously for other topical therapies. Melaleuca alternifolia (tea tree) oil gel (6%) for the treatment of recurrent herpes labialis. Carson CF, Ashton L, et al. J Antimicrob Chemother. 2001 Sep;48(3):450-1.

Histamine Skin Inflammation Reduced: Tea tree oil reduces histamine-induced skin inflammation. Koh KJ, Pearce AL, et al Flinders Medical, Bedford Park, Australia. Br J Dermatol. 2002 Dec;147(6):1212-7.

Itchy, Infected Skin Lesions Helped on Dogs: A standardised and stabilised 10% tea tree oil cream was tested against a commercial skin care cream (control cream) in the management of 57 dogs with with acute or chronic pruritic skin lesions, skin fold pyodermas and other forms of dermatitis in a DB study twice daily for 10 days. Success rates were 71% for the tea tree oil cream and 41% for the control cream (p = 0.04). The herbal cream was a fast-acting safe alternative to the standard therapy. Topical tea tree oil effective in canine localised pruritic dermatitis--a multi-centre randomised double-blind controlled clinical trial in the veterinary practice. Reichling J, Fitzi J, et al. Ruprecht-Karls-Universitat, Heidelberg. Dtsch Tierarztl Wochenschr. 2004 Oct;111(10):408-14. Inappropriate high doses can cause depression, weakness, incoordination and muscle tremors. This resolves in 2-3 days. Vet Hum Toxicol. 1994 Apr;36(2):139-42.

Mouthwash May Be Effective: In a 5-week study of 30 adults using mouthwashes of 0.2% tea tree oil, 2.5% garlic, or 0.12% chlorhexidine solutions, all were active against mutans streptococci, but only tea tree oil was against other oral microorganisms. Maintenance of reduced levels of microorganisms was observed only for garlic and tea tree oil. Unpleasant taste (chlorhexidine 40%, tea tree oil 30%, garlic 100%), burning sensation (chlorhexidine 40%, tea tree oil 60%, garlic 100%), bad breath (chlorhexidine 40%, tea tree oil 20%, garlic 90%), and nausea (chlorhexidine 0%, tea tree oil 10%, garlic 30%) were reported. Antimicrobial activity of garlic, tea tree oil, and chlorhexidine against oral microorganisms. Groppo FC, Ramacciato JC, Piracicaba Dental School, Sao Paulo, Brazil. Int Dent J. 2002 Dec;52(6):433-7.

Nickel-Induced Contact Hypersensitivity Helped by Tea Tree Oil: In a controlled study, 100% tea tree oil (TTO), a 5% TTO lotion, a placebo lotion, or 100% macadamia oil were applied at days 3 and 5 after nickel exposure. The flare area and erythema index were measured on days 3, 5 and 7. TTO (100%) significantly reduced the flare area and erythema index, but the 5% TTO lotion, the placebo lotion and the 100% macadamia oil were all without significant effect. Reduction of nickel-induced contact hypersensitivity reactions by topical tea tree oil in humans. Pearce AL, Finlay-Jones JJ, Hart PH. Flinders University, Adelaide, Australia. Inflamm Res. 2005 Jan;54(1):22-30.

Seborrheic Dermatitis Helped by Tea Tree Oil, Honey, and Various Medications: Seborrheic dermatitis is a superficial fungal disease of the skin, occurring in areas rich in sebaceous glands. Malassezia yeasts may cause an abnormal or inflammatory immune response. The azoles represent the largest class of antifungals used. In addition to their antifungal properties, some azoles, including bifonazole, itraconazole, and ketoconazole, have anti-inflammatory activity. Other topical antifungal agents, such as the allylamines (terbinafine), benzylamines (butenafine), hydroxypyridones (ciclopirox), and immunomodulators (pimecrolimus and tacrolimus), have also been effective. Tea tree oil (Melaleuca oil), honey, and cinnamic acid have antifungal activity against Malassezia species, which may be of benefit in the treatment of seborrheic dermatitis. Where seborrheic dermatitis is widespread, the use of an oral therapy, such as ketoconazole, itraconazole, and terbinafine, may be preferred. Role of antifungal agents in the treatment of seborrheic dermatitis. Gupta AK, Nicol K, Batra R. University of Toronto, Canada. Am J Clin Dermatol. 2004;5(6):417-22.

Staph Infections: Tea Tree Oil About as Good as Standard: Two topical MRSA eradication treatments were compared in 224 hospital patients: a standard treatment (mupirocin 2% nasal ointment, chlorhexidine gluconate 4% soap, silver sulfadiazine 1% cream) vs. a tea tree oil regimen (tea tree 10% cream, tea tree 5% body wash). Both were given for five days. The standard treatment cleared 49% of MRSA carriage vs. 41% with tea tree oil (P = 0.0286). Mupirocin was more effective at clearing nasal carriage (78%) than tea tree cream (47%; P = 0.0001) but tea tree treatment was more effective than chlorhexidine or silver sulfadiazine at clearing superficial skin sites and skin lesions. The tea tree preparations were effective, safe and well tolerated and could be considered in regimens for eradication of MRSA carriage. A randomized, controlled trial of tea tree topical preparations versus a standard topical regimen for the clearance of MRSA colonization. Dryden MS, Dailly S, Crouch M. Winchester, UK. J Hosp Infect. 2004 Apr;56(4):283-6.

Thrush Oral Yeast Infection May Have Been Helped in HIV Patients: A poor-quality, i.e. open-label, study in a university-based inner city HIV/AIDS clinic of 27 patients with AIDS and oral candidiasis clinically refractory to fluconazole found that 60% of patients using a melaleuca oral solution four times daily for 2-4 weeks reported improvement (7 patients no candidiasis and 8 patients clinically improved). Efficacy of alcohol-based and alcohol-free melaleuca oral solution for the treatment of fluconazole-refractory oropharyngeal candidiasis in patients with AIDS. Vazquez JA, Zawawi AA. Wayne State University, Detroit, Michigan. HIV Clin Trials. 2002 Sep-Oct;3(5):379-85.

Tinea Pedis: Tea Tree Oil Use Reported Increasingly Popular: Br J Dermatol. 2002 Dec;147(6):1212-7.

Tinea Pedis Helped: In a 4-week DB PC study of 158 patients with tinea pedis (athlete's foot) using twice daily treatment, marked improvement occurred in 68% of the 50% tea tree oil group and 72% of the 25% tea tree oil group, compared to 39% in the placebo group. Mycological cure was assessed by culture of skin scrapings taken at baseline and after 4 weeks of treatment. The mycological cure rate was 64% in the 50% tea tree oil group, compared to 31% in the placebo group. Four (3.8%) patients applying tea tree oil developed moderate to severe dermatitis that improved quickly on stopping the study medication. Treatment of interdigital tinea pedis with 25% and 50% tea tree oil solution: a randomized, placebo-controlled, blinded study. Satchell AC, Saurajen A, et al Camperdown, New South Wales, Australia. Australas J Dermatol. 2002 Aug;43(3):175-8.

Tinea Pedis Helped Although Tolnaftate Somewhat Better: In a DB PC study of 104 patients with tinea pedis, 10% w/w tea tree oil cream was compared with 1% tolnaftate and placebo creams. More tolnaftate-treated patients (85%) than tea tree oil (30%) and placebo-treated patients (21%) showed negative cultures at the end of therapy (p < 0.001). Scaling, inflammation, itching and burning was reduced in 64% with tea tree oil, 57% with tolnaftate, and 41% with placebo (p = 0.022 and p = 0.018). Tea tree oil in the treatment of tinea pedis. Tong MM, Altman PM, Barnetson RS. Camperdown, NSW. Australas J Dermatol. 1992;33(3):145-9.

Toenail Fungus: Butenafine with Tea Tree Creams Very Effective: Onychomycosis, a superficial fungal infection that destroys the entire nail unit, is very difficult to cure. In a 16-week DB PC study of 60 adults with the disease for 6-36 months, those using 2% butenafine hydrochloride with 5% Melaleuca alternifolia oil incorporated in a cream had an incredible 80% cure rate vs. 0% for placebo. Four patients in the active treatment group experienced subjective mild inflammation without discontinuing treatment. During follow-up, no relapse occurred in cured patients and no improvement was seen in medication-resistant and placebo participants. Treatment of toenail onychomycosis with 2% butenafine and 5% Melaleuca alternifolia (tea tree) oil in cream. Syed TA, Qureshi ZA, et al. University of California, San Francisco. Trop Med Int Health. 1999 Apr;4(4):284-7.

Toenail Fungus: Clotimazole and Two Tree Oil Equally Effective: In a 6-month DB PC study of 117 patients with onychomycosis, topical application of 1% clotrimazole solution compared with that of 100% Melaleuca alternifolia (tea tree) oil twice-daily did equally well based on culture cure (CL = 11%, TT = 18%) and clinical assessment documenting partial or full resolution (CL = 61%, TT = 60%). Three months later, continued improvement or resolution was equal as well (CL = 55%; TT = 56%). Comparison of two topical preparations for the treatment of onychomycosis: Melaleuca alternifolia (tea tree) oil and clotrimazole. Buck DS, Nidorf DM, Addino JG. University of Rochester. J Fam Pract. 1994 Jun;38(6):601-5. Ed: Using both together as above is probably the desired strategy.

Yeast Vaginitis: Tea tree oil is a home remedy for candida albicans yeast infections. Animal research has documented its effectiveness in a 5% solution. It is effective against yeast susceptible to or resistant to fluconazole. J Antimicrob Chemother. 2003 May;51(5):1223-9.  While effective, itching from allergic dermatitis to tea tree oil has been reported.  Should this occur, it should clear shortly after stopping the tea tree oil.

Thomas E. Radecki, M.D., J.D.

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